Viral sexually transmitted infections II Flashcards
What symptoms often accompany HSV infection?
Fever, inguinal adenopathy, malaise
What are the symptoms of recurrent HSV lesions?
- 3-5 discrete lesions 2. Vulvar irritation 3. Prodrome of tingling and pain 4. Heal within 7-10 days
What proportion of neonatal herpes infections involve encephalitis with or without skin lesions?
1/3
Is herpesvirus enveloped or non-enveloped?
Enveloped
What is the genome for HSV?
dsDNA
Where is latent infection established in HSV infection?
Sensory neuron cell body
What are the transmission routes for HSV?
- Direct contact 2. Saliva 3. Sexual transmission of genital herpes
What is seen on a positive Tzanck smear?
Cytopathic effect of HSV as well as large multinucleated cells
How is HSV-1 differentiated from HSV-2 in the lab?
- PCR 2. Immunocytochemistry to detect viral antigens
What is the treatment for genital herpes?
- Primary - oral antiviral 2. Recurrent - long term oral antiviral
Do anti-herpetic drugs act on the latent stage of infection?
No
What step in HSV infection is critical for acyclovir therapy to be effective?
Acyclovir must be phosphorylated by viral thymidine kinase
After phosphorylation by viral thymidine kinase, how does acyclovir inhibit HSV replication?
Triphosphate form is produced, which looks like a nucleotide 2. Viral DNA polymerase is inhibited
Acyclovir is effective against what population of cells during an HSV infection?
Only effective against the infected cells
What drugs are used in cases of acyclovir-resistant HSV infections?
Nonnucleoside inhibitors (eg Foscarnet)
What do nonnucleoside inhibitors target in HSV infections?
Viral DNA polymerase (but do not require thymidine kinase phosphorylation)
What is the morphology of HPV genital warts?
- Hyperkeratotic, firm, exophilic papules 2. 1-2 cm in diameter
What are the symptoms associated with HPV genital warts?
- 75% asymptomatic 2. Itching, pain, burning
HPV belongs to what virus family?
Papovaviridae
Is HPV enveloped or non-enveloped?
Non-enveloped
What is the HPV genome?
dsDNA
How is HPV replication linked to tissue differentiation?
- HPV replicates in basal epithelium, then moves upward during later stages of replication 2. Three dimensional structure is critical for replication
Which HPV strains are at high risk for cancer development?
- 16, 18, 31, 33 2. Mucosal / anogenital class
Which HPV strain has the highest prevalence of cervical cancer?
HPV-16
What is the pathogenesis of HPV-induced cancer?
Infected cells leave HPV life cycle and upregulate E6 and E7 by inactivating negative regulator E2
What are the roles of E6 and E7 in a cell?
E6 inactivates p53, E7 inactivates Rb
What is the relationship between E6, E7, and E2?
E2 is a negative regulator of E6 and E7
What are histological markers for HPV?
Hyperkeratosis and koilocytes
What are koilocytes?
Enlarged keratinocytes that contain irregular hyperchromatic nuclei surrounded by a characteristic halo (seen in HPV pap smears)
What laboratory tests are used to diagnose HPV?
PCR, pap smear
HPV vaccines are made in what medium?
Yeast
HPV vaccines are prepared from what proteins?
Viral capsid proteins
Gardasil protects against which HPV strains?
6, 11, 16, 18
Cervarix protects against which HPV vaccines?
16, 18
What are the HPV vaccination recommendations for girls?
Quadrivalent or bivalent vaccine for all girls 11-12 yo
What are the HPV vaccination recommendations for boys?
Quadrivalent for all boys 11-12 yo
